Electron Paramagnetic Resonance Spectrometry-based Assessment of Free Radicals Scavenging Potential of N-acetyl Tryptophan Glucoside

Poonam Malhotra; Yana Karamalakova; Galina Nikolova; Darshana Singh; Raj Kumar

doi:10.14429/dlsj.2.11672

Poonam Malhotra Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences, Delhi
Yana Karamalakova Department of Chemistry and Biochemistry, Trakia University, Stara Zagora
Galina Nikolova Department of Chemistry and Biochemistry, Trakia University, Stara Zagora
Darshana Singh Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences, Delhi
Raj Kumar Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences, Delhi

DOI: https://doi.org/10.14429/dlsj.2.11672

Keywords: Electron paramagnetic resonance spectrometry, Bacterial metabolite, Radiation protection, Oxidative stress, Free radicals

Abstract

Gamma radiation generates free radicals in biological system by inducing cellular water radiolysis. If not neutralised, free radicals oxidise vital bio-macromolecules causing structural and functional impairment and contribute to cell death. In present study, free radical scavenging activities of a novel bacterial secondary metabolite, N-acetyl tryptophan glucoside (NATG) was assessed against gamma-radiation induced damage in vitro and in vivo models. Effect of irradiated NATG (UV and gamma radiation 8 Gy and 20 Gy) on its free radical (DPPH radicals) and SOD-like activity was evaluated using EPR spectrometry. To assess the effect of NATG irradiation on its antioxidant potential, EPR based ascorbate, PBN and NO radicals scavenging activities were evaluated in blood and spleen tissue of strain A male mice. Results of the study indicated significant (p < 0.05) increase in DPPH radicals scavenging ability of irradiated NATG as compared to un-irradiated NATG. Similarly, irradiated NATG exhibited significant (p < 0.05) elevation in SOD-like activity as compared to control. Subsequently, NATG treatment displayed enhanced antioxidant activity as evident by significant (p < 0.05) decline in ascorbate, PBN and NO radicals at 1 h and 2h in blood and spleen tissues homogenate of treated mice as compared to control group. In conclusion, NATG possesses significant free radicals scavenging and radio protective capabilities against gamma radiation induced oxidative stress.

Author Biographies

Poonam Malhotra, Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences, Delhi

Ms Poonam Malhotra has received her MPhil and submitted PhD (Life Sciences)at Bharathiar University, Coimbatore, India. She has vast experience working in the areas of radiation biology, oxidative stress, bacterial secondary metabolites, their effects on the mammalian immune system and novel drug development using in vitro and in vivo models.

Yana Karamalakova, Department of Chemistry and Biochemistry, Trakia University, Stara Zagora

Dr Yana Karamalakova received her PhD from Trakia University, Stara Zagora, Bulgaria. Presently working as Assistant Professor at Trakia University, Stara Zagora, Bulgaria. She has immense knowledge in the field of organic chemistry, EPR studies and has made significant contributions in the isolation and characterisation of antioxidant molecules from herbal products.

Galina Nikolova, Department of Chemistry and Biochemistry, Trakia University, Stara Zagora

Dr Galina Nikolovahas received her PhD in bioorgani cchemistryfrom Trakia University, Stara Zagora, Bulgaria and is currently working as Head Assistant at Trakia University, Stara Zagora, Bulgaria. Shehas expertise in the drug development andevaluation of secondary isolates and nutraceuticals as potential herbal antioxidants.

Darshana Singh, Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences, Delhi

Ms Darshana Singh is presently working as Junior Research Fellow at Institute of Nuclear Medicine and Allied Sciences (INMAS), DRDO, Delhi. She has received her MSc from Agra University, Agra. She is currently working on drug development from secondary metabolites isolated from radioresistant bacteria and its effects on hematopoietic stem cells.

Raj Kumar, Division of Radioprotective Drug Development and Research, Institute of Nuclear Medicine and Allied Sciences, Delhi

Dr Raj Kumar is currently working as Scientist E and heading the Radiation Biotechnology Group at Institute of Nuclear Medicine and Allied Sciences (INMAS), DRDO, Delhi. He received his PhD Biotechnology from IIT, Roorkee. He is involved in development of novel drug candidates from secondary metabolites isolated from radioresistant bacteria and has extensive knowledge in the field of radiation biology, oxidative stress, nutraceuticals and radiation countermeasure agents.